| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * License); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| #ifndef ENCODING_GORILLA_DECODER_H |
| #define ENCODING_GORILLA_DECODER_H |
| |
| #include <climits> |
| |
| #include "common/allocator/byte_stream.h" |
| #include "decoder.h" |
| #include "encode_utils.h" |
| #include "gorilla_encoder.h" |
| #include "utils/db_utils.h" |
| #include "utils/util_define.h" |
| |
| namespace storage { |
| |
| template <typename T> |
| class GorillaDecoder : public Decoder { |
| public: |
| GorillaDecoder() { reset(); } |
| |
| ~GorillaDecoder() override = default; |
| |
| void reset() { |
| type_ = common::GORILLA; |
| stored_value_ = 0; |
| stored_leading_zeros_ = INT32_MAX; |
| stored_trailing_zeros_ = 0; |
| bits_left_ = 0; |
| first_value_was_read_ = false; |
| has_next_ = false; |
| buffer_ = 0; |
| } |
| |
| FORCE_INLINE bool has_next() { return has_next_; } |
| FORCE_INLINE bool has_remaining(const common::ByteStream &buffer) { |
| return buffer.has_remaining() || has_next(); |
| } |
| |
| // If empty, cache 8 bits from in_stream to 'buffer_'. |
| void flush_byte_if_empty(common::ByteStream &in) { |
| if (bits_left_ == 0) { |
| uint32_t read_len = 0; |
| in.read_buf(&buffer_, 1, read_len); |
| bits_left_ = 8; |
| } |
| } |
| |
| // Reads the next bit and returns true if the next bit is 1, otherwise 0. |
| bool read_bit(common::ByteStream &in) { |
| bool bit = ((buffer_ >> (bits_left_ - 1)) & 1) == 1; |
| bits_left_--; |
| flush_byte_if_empty(in); |
| return bit; |
| } |
| |
| /* |
| * Reads a long from the next X bits that represent the least significant |
| * bits in the long value. |
| * @bits: How many next bits are reader from the stream |
| * return: long value that was reader from the stream |
| */ |
| int64_t read_long(int bits, common::ByteStream &in) { |
| int64_t value = 0; |
| while (bits > 0) { |
| if (bits > bits_left_ || bits == 8) { |
| // Take only the bits_left_ "least significant" bits. |
| uint8_t d = (uint8_t)(buffer_ & ((1 << bits_left_) - 1)); |
| value = (value << bits_left_) + (d & 0xFF); |
| bits -= bits_left_; |
| bits_left_ = 0; |
| } else { |
| // Shift to correct position and take only least significant |
| // bits. |
| uint8_t d = |
| (uint8_t)((((uint8_t)buffer_) >> (bits_left_ - bits)) & |
| ((1 << bits) - 1)); |
| value = (value << bits) + (d & 0xFF); |
| bits_left_ -= bits; |
| bits = 0; |
| } |
| flush_byte_if_empty(in); |
| } |
| return value; |
| } |
| |
| // Read the control bits |
| uint8_t read_next_control_bit(int max_bits, common::ByteStream &in) { |
| uint8_t value = 0x00; |
| for (int i = 0; i < max_bits; i++) { |
| value <<= 1; |
| if (read_bit(in)) { |
| value |= 0x01; |
| } else { |
| break; |
| } |
| } |
| return value; |
| } |
| |
| T read_next(common::ByteStream &in); |
| virtual T cache_next(common::ByteStream &in); |
| T decode(common::ByteStream &in); |
| |
| // interface from Decoder |
| int read_boolean(bool &ret_value, common::ByteStream &in); |
| int read_int32(int32_t &ret_value, common::ByteStream &in); |
| int read_int64(int64_t &ret_value, common::ByteStream &in); |
| int read_float(float &ret_value, common::ByteStream &in); |
| int read_double(double &ret_value, common::ByteStream &in); |
| int read_String(common::String &ret_value, common::PageArena &pa, |
| common::ByteStream &in); |
| |
| public: |
| common::TSEncoding type_; |
| T stored_value_; |
| int stored_leading_zeros_; |
| int stored_trailing_zeros_; |
| int bits_left_; |
| bool first_value_was_read_; |
| bool has_next_; |
| uint8_t buffer_; |
| }; |
| |
| template <> |
| FORCE_INLINE int32_t |
| GorillaDecoder<int32_t>::read_next(common::ByteStream &in) { |
| uint8_t control_bits = read_next_control_bit(2, in); |
| uint8_t significant_bits = 0; |
| int32_t xor_value = 0; |
| switch (control_bits) { |
| case 3: // case '11': use new leading and trailing zeros |
| stored_leading_zeros_ = |
| (int)read_long(LEADING_ZERO_BITS_LENGTH_32BIT, |
| in); // todo: int or int32_t? |
| significant_bits = |
| (uint8_t)read_long(MEANINGFUL_XOR_BITS_LENGTH_32BIT, in); |
| significant_bits++; |
| stored_trailing_zeros_ = VALUE_BITS_LENGTH_32BIT - |
| significant_bits - stored_leading_zeros_; |
| // missing break is intentional, we want to overflow to next one |
| case 2: // case '10': use stored leading and trailing zeros |
| xor_value = (int32_t)read_long(VALUE_BITS_LENGTH_32BIT - |
| stored_leading_zeros_ - |
| stored_trailing_zeros_, |
| in); |
| xor_value = static_cast<uint32_t>(xor_value) |
| << stored_trailing_zeros_; |
| stored_value_ ^= xor_value; |
| // missing break is intentional, we want to overflow to next one |
| default: // case '0': use stored value |
| return stored_value_; |
| } |
| return stored_value_; |
| } |
| |
| template <> |
| FORCE_INLINE int64_t |
| GorillaDecoder<int64_t>::read_next(common::ByteStream &in) { |
| uint8_t control_bits = read_next_control_bit(2, in); |
| |
| uint8_t significant_bits = 0; |
| int64_t xor_value = 0; |
| switch (control_bits) { |
| case 3: { // case '11': use new leading and trailing zeros |
| stored_leading_zeros_ = |
| (int)read_long(LEADING_ZERO_BITS_LENGTH_64BIT, |
| in); // todo: int or int32_t? |
| significant_bits = |
| (uint8_t)read_long(MEANINGFUL_XOR_BITS_LENGTH_64BIT, in); |
| significant_bits++; |
| stored_trailing_zeros_ = VALUE_BITS_LENGTH_64BIT - |
| significant_bits - stored_leading_zeros_; |
| // missing break is intentional, we want to overflow to next one |
| } |
| case 2: { // case '10': use stored leading and trailing zeros |
| xor_value = |
| read_long(VALUE_BITS_LENGTH_64BIT - stored_leading_zeros_ - |
| stored_trailing_zeros_, |
| in); |
| xor_value = static_cast<uint64_t>(xor_value) |
| << stored_trailing_zeros_; |
| stored_value_ ^= xor_value; |
| // missing break is intentional, we want to overflow to next one |
| } |
| default: { // case '0': use stored value |
| return stored_value_; |
| } |
| } |
| return stored_value_; |
| } |
| |
| template <> |
| FORCE_INLINE int32_t |
| GorillaDecoder<int32_t>::cache_next(common::ByteStream &in) { |
| read_next(in); |
| if (stored_value_ == GORILLA_ENCODING_ENDING_INTEGER) { |
| has_next_ = false; |
| } |
| return stored_value_; |
| } |
| |
| template <> |
| FORCE_INLINE int64_t |
| GorillaDecoder<int64_t>::cache_next(common::ByteStream &in) { |
| read_next(in); |
| if (stored_value_ == GORILLA_ENCODING_ENDING_LONG) { |
| has_next_ = false; |
| } |
| return stored_value_; |
| } |
| |
| template <> |
| FORCE_INLINE int32_t GorillaDecoder<int32_t>::decode(common::ByteStream &in) { |
| int32_t ret_value = stored_value_; |
| if (UNLIKELY(!first_value_was_read_)) { |
| flush_byte_if_empty(in); |
| stored_value_ = (int32_t)read_long(VALUE_BITS_LENGTH_32BIT, in); |
| first_value_was_read_ = true; |
| ret_value = stored_value_; |
| } |
| cache_next(in); |
| return ret_value; |
| } |
| |
| template <> |
| FORCE_INLINE int64_t GorillaDecoder<int64_t>::decode(common::ByteStream &in) { |
| int64_t ret_value = stored_value_; |
| if (UNLIKELY(!first_value_was_read_)) { |
| flush_byte_if_empty(in); |
| stored_value_ = read_long(VALUE_BITS_LENGTH_64BIT, in); |
| first_value_was_read_ = true; |
| ret_value = stored_value_; |
| } |
| cache_next(in); |
| return ret_value; |
| } |
| |
| class FloatGorillaDecoder : public GorillaDecoder<int32_t> { |
| public: |
| int read_boolean(bool &ret_value, common::ByteStream &in); |
| int read_int32(int32_t &ret_value, common::ByteStream &in); |
| int read_int64(int64_t &ret_value, common::ByteStream &in); |
| int read_float(float &ret_value, common::ByteStream &in); |
| int read_double(double &ret_value, common::ByteStream &in); |
| |
| float decode(common::ByteStream &in) { |
| int32_t value_int = GorillaDecoder<int32_t>::decode(in); |
| return common::int_to_float(value_int); |
| } |
| |
| int32_t cache_next(common::ByteStream &in) { |
| read_next(in); |
| if (stored_value_ == |
| common::float_to_int(GORILLA_ENCODING_ENDING_FLOAT)) { |
| has_next_ = false; |
| } |
| return stored_value_; |
| } |
| }; |
| |
| class DoubleGorillaDecoder : public GorillaDecoder<int64_t> { |
| public: |
| int read_boolean(bool &ret_value, common::ByteStream &in); |
| int read_int32(int32_t &ret_value, common::ByteStream &in); |
| int read_int64(int64_t &ret_value, common::ByteStream &in); |
| int read_float(float &ret_value, common::ByteStream &in); |
| int read_double(double &ret_value, common::ByteStream &in); |
| |
| double decode(common::ByteStream &in) { |
| int64_t value_long = GorillaDecoder<int64_t>::decode(in); |
| return common::long_to_double(value_long); |
| } |
| |
| int64_t cache_next(common::ByteStream &in) { |
| read_next(in); |
| if (stored_value_ == |
| common::double_to_long(GORILLA_ENCODING_ENDING_DOUBLE)) { |
| has_next_ = false; |
| } |
| return stored_value_; |
| } |
| }; |
| |
| typedef GorillaDecoder<int32_t> IntGorillaDecoder; |
| typedef GorillaDecoder<int64_t> LongGorillaDecoder; |
| |
| // wrap as Decoder interface |
| template <> |
| FORCE_INLINE int IntGorillaDecoder::read_boolean(bool &ret_value, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| template <> |
| FORCE_INLINE int IntGorillaDecoder::read_int32(int32_t &ret_value, |
| common::ByteStream &in) { |
| ret_value = decode(in); |
| return common::E_OK; |
| } |
| template <> |
| FORCE_INLINE int IntGorillaDecoder::read_int64(int64_t &ret_value, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| template <> |
| FORCE_INLINE int IntGorillaDecoder::read_float(float &ret_value, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| template <> |
| FORCE_INLINE int IntGorillaDecoder::read_double(double &ret_value, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| template <> |
| FORCE_INLINE int IntGorillaDecoder::read_String(common::String &ret_value, |
| common::PageArena &pa, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| template <> |
| FORCE_INLINE int LongGorillaDecoder::read_boolean(bool &ret_value, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| template <> |
| FORCE_INLINE int LongGorillaDecoder::read_int32(int32_t &ret_value, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| template <> |
| FORCE_INLINE int LongGorillaDecoder::read_int64(int64_t &ret_value, |
| common::ByteStream &in) { |
| ret_value = decode(in); |
| return common::E_OK; |
| } |
| template <> |
| FORCE_INLINE int LongGorillaDecoder::read_float(float &ret_value, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| template <> |
| FORCE_INLINE int LongGorillaDecoder::read_double(double &ret_value, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| template <> |
| FORCE_INLINE int LongGorillaDecoder::read_String(common::String &ret_value, |
| common::PageArena &pa, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| FORCE_INLINE int FloatGorillaDecoder::read_boolean(bool &ret_value, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| FORCE_INLINE int FloatGorillaDecoder::read_int32(int32_t &ret_value, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| FORCE_INLINE int FloatGorillaDecoder::read_int64(int64_t &ret_value, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| FORCE_INLINE int FloatGorillaDecoder::read_float(float &ret_value, |
| common::ByteStream &in) { |
| ret_value = decode(in); |
| return common::E_OK; |
| } |
| FORCE_INLINE int FloatGorillaDecoder::read_double(double &ret_value, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| FORCE_INLINE int DoubleGorillaDecoder::read_boolean(bool &ret_value, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| FORCE_INLINE int DoubleGorillaDecoder::read_int32(int32_t &ret_value, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| FORCE_INLINE int DoubleGorillaDecoder::read_int64(int64_t &ret_value, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| FORCE_INLINE int DoubleGorillaDecoder::read_float(float &ret_value, |
| common::ByteStream &in) { |
| ASSERT(false); |
| return common::E_NOT_SUPPORT; |
| } |
| FORCE_INLINE int DoubleGorillaDecoder::read_double(double &ret_value, |
| common::ByteStream &in) { |
| ret_value = decode(in); |
| return common::E_OK; |
| } |
| |
| } // end namespace storage |
| #endif // ENCODING_GORILLA_DECODER_H |
